/***********************************************************************
Write a recursive function called `factorial` that takes an integer, `num`,
and returns the factorial of `num`. Assume the value of `num` is greater 
than or equal to 1.

A factorial is the number get when multiplying a number by itself minus one
all the way down to 1 (but not 0)! We represent them with an exclamation
point, also sometimes called a "bang" in programming.

5! = 5 x 4 x 3 x 2 x 1 = 120

Examples:

factorial(1); // => 1
factorial(3); // => 6
factorial(5); // => 120
***********************************************************************/

function factorial( num ) {
  if ( num === 1 ) {
    return 1;
  }

  return num * factorial( num - 1 );
}

/**************DO NOT MODIFY ANYTHING UNDER THIS LINE*****************/
module.exports = factorial;
